Chitosan Membranes for Direct Methanol Fuel Cell Applications

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Fuel cells require advanced membrane materials for efficient operation.
• Silica/chitosan composites offer potential for improved membrane properties.

Purpose of the Study:

• To fabricate silica/chitosan composite membranes using solution casting.
• To evaluate their physical characteristics and suitability for fuel cell applications.
• To determine the impact of silica content on membrane performance.

Main Methods:

• Solution casting method employed for membrane fabrication.
• Chitosan (5 g) and varying silica (2%, 4%) dosages used.
• Stirring at constant speed for 2 hours.
• Characterization of water absorption, proton conductivity, and methanol permeability.

Main Results:

• Successful modification of chitosan membranes with silica confirmed.
• Optimal membrane identified with 4% s-SiO2 (Sol-gel method).
• Achieved proton conductivity of 0.234 cm/s, water uptake of 56.21%, and reduced methanol permeability (0.99 × 10⁻⁷ cm²/s initially).
• Lower water uptake at higher silica content presents an ongoing challenge.

Conclusions:

• Fabricated silica/chitosan membranes demonstrate exceptional proton conductivity.
• Reduced methanol permeability indicates suitability for fuel cell applications.
• Further optimization needed to address water uptake challenges in high-silica content membranes.